The Wisconsin National Primate Research Center (WNPRC) supports an active HIV/AIDS research program with greater than $8,000,000 in funding from the National Institutes of Health and private entities. WNPRC investigators infect rhesus macaques of Indian ancestry and cynomolgus macaques of Mauritian origin with Simian Immunodeficiency Virus (SIV) to study HIV pathogenesis and vaccine development. Currently, 205 macaques (153 rhesuses, 52 cynomolgus) assigned to 27 individual projects covered by 20 different animal care and use protocols are utilized for HIV/AIDS research at the WNPRC. WNPRC investigators acquire macaques for HIV/AIDS projects from the Center's own Specific Pathogen Free (SPF) breeding colony. This proposal seeks to acquire funding to replace aging stationary caging in the SPF breeding area with contemporary mobile caging. The proposal also seeks funding to augment the existing mobile caging to improve the psychological well being of the SPF colony and the SIV-infected macaques housed at the WNPRC. Finally, this proposal also seeks funding to upgrade the physical infrastructure (e.g., doors, flooring) of the SPF and SIV-infected macaque housing areas of the WNPRC. Successful completion of the aims outlined in this proposal will ensure that WNPRC investigators performing ZHIV/AIDS research are provided with quality animals and that the psychological health of these animals is protected.